Quickest way to solve this problem is to take it to your lbs and have them install a new one. It shouldnt cost you more than $30 incl labour and possibly as low as $15. The slower way is to figure out whether your raleigh and mtb bb's match across three parameters:
1. bb shell width
2. bb spindle length
3. bb threading type.
You can get info about all this stuff at http://sheldonbrown.com/gloss_bo-z.html#bottom
. I would classify this project as "hard for a newb" so unless you enjoy this type of thing you might want to lbs it.
Edit: A "hybrid" approach would be to go to your lbs and have them figure out what kind of bb you need, then buy that bb along with a bb tool & crank puller from them and do the rest yourself. Thats how I did my first bb replacement. With the tols it may well cost you more than a straight up bb replacement but you will have profited by gaining some knowhow.
Double edit: If youre planning to convert this raleigh to fixed/ss that opens up a whole nother can o worms with chainline.
Last edited by mander; 02-13-07 at 08:41 PM.